U.S. patent number 7,678,718 [Application Number 11/680,939] was granted by the patent office on 2010-03-16 for base layer apparel.
This patent grant is currently assigned to Longworth Industries, Inc.. Invention is credited to Tony G. Connor, William W. Harris.
United States Patent |
7,678,718 |
Harris , et al. |
March 16, 2010 |
Base layer apparel
Abstract
A base layer apparel is provided that is formed from a single or
double-knit fabric. The fabric is formed of ring spun fire
resistant yarns that are an intimate blend of at least 60 percent
modacrylic fibers and up to 40 percent fire-resistant viscose
fibers. Anti-microbial and wicking treatments may be applied to the
knit fabric.
Inventors: |
Harris; William W. (Pinehurst,
NC), Connor; Tony G. (Eagle Springs, NC) |
Assignee: |
Longworth Industries, Inc.
(West End, NC)
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Family
ID: |
39721547 |
Appl.
No.: |
11/680,939 |
Filed: |
March 1, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20080214076 A1 |
Sep 4, 2008 |
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Current U.S.
Class: |
442/310; 66/171;
57/255; 57/252; 442/318; 442/308; 442/123; 428/921; 428/920; 2/458;
2/456; 2/400; 2/113 |
Current CPC
Class: |
D04B
1/16 (20130101); D02G 3/443 (20130101); A62B
17/003 (20130101); Y10S 428/92 (20130101); Y10T
442/425 (20150401); Y10T 442/2525 (20150401); D10B
2201/24 (20130101); D10B 2321/101 (20130101); Y10T
442/488 (20150401); Y10S 428/921 (20130101); Y10T
442/2631 (20150401); Y10T 442/438 (20150401) |
Current International
Class: |
D04B
1/14 (20060101); A41B 1/00 (20060101); D04B
1/16 (20060101); D04B 1/24 (20060101); D04B
1/22 (20060101); A41B 9/06 (20060101); A41B
9/12 (20060101); D02G 3/02 (20060101); D02G
3/04 (20060101) |
Field of
Search: |
;442/59,123,85,86,308,304,310,318 ;57/252,255
;66/169R,170-171,175-177,202 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2152542 |
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Aug 1985 |
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GB |
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2179067 |
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Feb 1987 |
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GB |
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Other References
Anand, S.C. and S.J. Garvey, "Flame Retardancy". Knitting
International, vol. 104, No. 1238, Jun. 1997. cited by examiner
.
Ozcan, et al. "Effect of Gray Fabric Properties on Flame Resistance
of Knitted Fabric", Textile Research Journal 73(10), 883-891,
Otcober 2003. cited by examiner.
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Primary Examiner: Chriss; Jennifer A
Attorney, Agent or Firm: Womble Carlyle Sandridge &
Rice, PLLC
Claims
We claim:
1. A garment, comprising: (a) an article of base layer apparel for
wear adjacent the skin and selected from the group consisting of
long underwear, short underwear, and undershirts, and formed of a
knit fabric, comprising: (i) ring spun flame-resistant yarns
comprising an intimate blend of between 74 percent and 80 percent
modacrylic fibers and between 20 percent and 26 percent
flame-resistant viscose fibers, wherein the modacrylic constituent
has at least 50 percent acrylonitrile units, and further wherein
the yarn size is between 30/1 cc and 36/1 cc, and the modacrylic
fibers have a denier of about 1.5; (ii) wherein the yarns are
formed into a double knit construction having a first skin-contact
layer and a second layer, the first skin-contact layer having first
open spaces and a second outer layer having second open spaces
larger than the first open spaces; (b) wherein the article of base
layer apparel is flame resistant, moisture absorbent, and has a
soft hand suitable for wear in direct contact with a wearer's skin
for extended periods in high temperature and high humidity
environments.
2. The base layer apparel of claim 1 wherein the modacrylic fibers
are about 2 inches in length and the yarn size is 30/1 cc.
3. An undergarment, comprising: (a) an article of base layer
apparel for wear adjacent the skin and selected from the group
consisting of long underwear, short underwear, and undershirts, and
formed of a jersey knit fabric, comprising: (i) ring spun
flame-resistant yarns comprising an intimate blend of at between 74
percent and 80 percent modacrylic fibers and between 20 percent and
26 percent flame-resistant viscose fibers, wherein the modacrylic
constituent has at least 50 percent acrylonitrile units, and
further wherein the yarn size is between 30/1 cc and 36/1 cc, and
the modacrylic fibers have a denier of about 1.5; and (b) wherein
the article of base layer apparel is flame resistant, moisture
absorbent, and has a soft hand suitable for wear in direct contact
with a wearer's skin for extended periods in high temperature and
high humidity environments.
4. A T-shirt, comprising: (a) a knit fabric forming a tubular body
portion open at the bottom and having a pair of arm openings and a
neck opening, the knit fabric comprising: (i) ring spun
fire-resistant yarns comprising an intimate blend of at between 74
percent and 80 percent modacrylic fibers and between 20 percent and
26 percent fire-resistant viscose fibers, wherein the modacrylic
constituent has at least 50 percent acrylonitrile units, and
further wherein the yarn size is between 30/1 cc and 36/1 cc, and
the modacrylic fibers have a denier of about 1.5; and (b) wherein
the T-shirt is flame resistant, moisture absorbent, and has a soft
hand suitable for wear in direct contact with a wearer's skin for
extended periods in high temperature and high humidity
environments.
5. The T-shirt of claim 4 wherein the yarns are formed into a
double knit construction having one of the layers comprising an
open mesh construction having open spaces larger than the other of
the double knit layers.
6. The garment of claim 1, wherein the knit fabric comprises at
least one of a wicking treatment and an anti-microbial treatment
applied to the fabric.
7. The undergarment of claim 3, wherein the knit fabric comprises
at least one of a wicking treatment and an anti-microbial treatment
applied to the fabric.
8. The undergarment of claim 3, wherein the modacrylic fibers are
about 2 inches in length and the yarn size is 30/1 cc.
9. The T-shirt of claim 4, wherein the knit fabric comprises at
least one of a wicking treatment and an anti-microbial treatment
applied to the fabric.
Description
FIELD OF THE INVENTION
The present invention relates generally to textile products, and
more particularly, to a flame resistant, base layer apparel and
fabric therefore.
BACKGROUND OF THE INVENTION
"Base layer" apparel conventionally refers to garments that are
worn against the skin, often as inner garments such as underwear,
T-shirts, and brassieres, beneath outerwear such as trousers,
shirts/blouses, skirts, etc. Such garments are formed to have a
soft touch, or hand, and among other things, provide support
against the skin, and serve to absorb perspiration during normal
daily activities. Most of these garments are made substantially of
cotton, a natural fiber that is inexpensive and quite suitable for
most wearers and most applications.
Unfortunately, however, base layer garments formed of conventional
yarns and fabrics are not adequate for wear in occupations defined
by potential hazardous exposures to sources of ignition, or high
voltage electricity. While cotton base layer apparel may be treated
to afford some flame-resistance, the chemical treatment on the
cotton fibers degrades over the life of the garment through
physical wear and laundering. This, of course, is unsatisfactory
for base layer apparel for military personnel that is subjected to
extreme wear conditions. Coupled with the constant risk in combat
areas of bodily harm from the ignition of highly flammable
materials such as gas and explosives, incendiary, or
flame-producing munitions, something more is needed to personal
protection.
While some flame-resistant yarns and fibers are now known for use
in manufacturing apparel, these materials alone do not provide a
satisfactory degree of comfort when formed into base layer apparel
worn adjacent the skin. Most of these synthetic flame resistant
materials also are generally hydrophobic, meaning that they lack an
affinity to and absorbency for moisture and/or body
perspiration.
What is needed is a fabric for base layer apparel that provides not
only adequate, long-term, flame resistance, but that also is
moisture absorbent and has a soft hand that is comfortable to the
wearer under conditions such as high temperature and high humidity,
and for extended periods.
SUMMARY OF THE INVENTION
A primary aspect of the present invention is a base layer apparel
made up of at least about sixty percent modacylic fibers and up to
about forty percent flame resistant viscose fibers. As used herein,
"base layer" refers to fabric or apparel constructions for wear as
a first layer directly against the skin of the wearer; e.g.,
underwear, T-shirts, and thermal undergarments.
The fabric for the base layer apparel may be formed in various
constructions. It may be jersey knit in a single layer or may be a
double-knit construction having first and second sides formed on a
circular knitting machine of the type having needles in the
cylinder and dial. The yarns are ring-spun fire resistant yarns
comprising an intimate blend of at least about sixty percent
modacrylic fibers and up to about forty percent fire-resistant
viscose fibers. Preferably, the modacrylic fibers comprise between
about seventy-four percent and eighty percent of the intimate blend
and the fire resistant viscose fibers comprise between about twenty
percent and twenty-six percent of the intimate blend. Yarn sizes
found most suitable for the knit fabric construction are between
about 30/1 cc and 36/1 cc, however other sizes may also be
satisfactory.
One of the two sides of the double-knit fabric version is knitted
as an open mesh, or foramenous, structure. This open mesh side is
defined by openings between the yarns that are larger than the
openings between the yarns on the opposite side of the fabric. As
will be more apparent from the detailed description that follows,
this double-knit construction is helpful to induce moisture
migration (wicking) outwardly away from the wearer's skin.
Chemical treatments may be applied to the fabric during dyeing and
fabric finishing. One chemical is a wicking agent that may be
applied during the jet dyeing process to facilitate movement of
moisture throughout the fabric during wear. For certain types of
base layer apparel, such as underwear and T-shirts, an
anti-microbial treatment also may be applied during or after the
dyeing process of the greige fabric to inhibit or prevent the
growth of micro-organisms.
The embodiments described above are exemplary only, and other
aspects of the present invention will become apparent to those
skilled in the art after a reading of the following description of
the preferred embodiment in combination with the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of one surface of the
double-knit fabric version of the present invention;
FIG. 2 is a schematic representation of the opposite, open mesh
surface of the double-knit fabric version of the present
invention;
FIG. 3 is the knitting diagram for the double-knit fabric
illustrated in FIGS. 1 and 2; and
FIG. 4 is representative of one type of apparel formed from the
double-knit fabric of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Certain exemplary embodiments of the present invention are
described below and illustrated in the attached Figures. The
embodiments described are only for purposes of illustrating the
present invention and should not be interpreted as limiting the
scope of the invention, which, of course, is limited only by the
claims below. Other embodiments of the invention, and certain
modifications and improvements of the described embodiments, will
occur to those skilled in the art, and all such alternate
embodiments, modifications and improvements are within the scope of
the present invention.
DEFINITIONS
"Anti-Microbial" describes the property of a material or substance
that tends to destroy microbes, prevent their development, or
inhibit their pathogenic action.
"Base layer" refers to fabric or apparel constructions for wear as
a first layer directly against the skin of the wearer
"Double-Knit" describes a fabric formed on a circular knitting
machine equipped with two sets of latch needles situated at right
angles to each other (dial and cylinder)
"Flame resistant," as used herein, describes a material that burns
slowly or is self-extinguishing after removal of an external source
of ignition. A fabric or yarn can be flame resistant because of the
inherent properties of the material, the twist level of the yarn,
the fabric construction, the presence of flame retardants, or a
combination thereof.
"Intimate blend" refers to a technique of mixing two or more
dissimilar fibers in a very uniform mixture.
"Mesh," or "Open Mesh," as used herein, describes a fabric
construction characterized by open spaces between the yarns in one
or more layers, plies, or sides of the fabric.
"Wicking" refers to the action of the dispersing or spreading of
moisture or liquid over a given area
One aspect of the present invention is directed to a base layer
apparel, such as underwear and T-shirts (FIG. 4) that addresses the
problems described above. More particularly, the base layer apparel
of the present invention is formed from a fabric comprising yarns
that are an intimate blend of flame resistant fibers, as described
in greater detail below.
In one preferred embodiment, the fabric is a double-knit
construction having first and second surfaces or sides formed on a
circular knitting machine. Each of the surfaces includes ring-spun
fire resistant yarns. In this embodiment, the yarns are formed from
an intimate blend of modacrylic staple fibers and flame resistant
(FR) viscose staple fibers.
Modacrylics are polymers that have between thirty-five percent and
eighty-five percent acrylonitrile units, modified by other chemical
modifiers such as vinyl chloride. All modacrylics have an
inherently flame-resistant character to some extent; however, it
has been found that fabrics formed from modacrylic yarns having at
least about fifty percent by weight of acrylonitrile units will
provide excellent flame resistance. That is, they will not melt and
drip, or continue to burn when a source of ignition is removed. One
suitable modacrylic is a short staple fiber such as Kanecaron.RTM.
Protex, manufactured by Kaneka Corporation, Osaka, Japan. These
fibers have a tenacity of greater than about two grams/denier, and
preferably about three grams/denier. In one embodiment, the staples
are two inches in length and have a denier of about 1.5, however
other fiber deniers are also within the scope of the invention. In
addition to their good flame resistance, modacrylic fibers high a
high degree of washability, meaning that soils or stains are more
easily removed during laundering. Modacrylic fibers, and yarns
formed exclusively therefore, do have some inherent drawbacks. In
particular, modacrylic yarns do not hold knitted stitches well. As
a result, fabrics formed from these yarns alone often lack
dimensional stability. When subjected to wear and laundering, the
courses and wales of the fabric tend to stretch, or "grow."
Viscose fibers, sometimes known as "rayon," are derived from wood
pulp. Flame resistant viscose fibers are viscose fibers that are
chemically treated to impart heat and flame resistance to the
fibers. As such, these treated fibers are adapted for applications
in which protection is sought from fire, radiant heat, electrical
arcs, etc. One suitable flame resistant viscose fiber is
LENZING.RTM., available from Lenzing Fibers with facilities in
Mobile, Ala. While rayon generally has poor washability in
comparison to modacrylic, it is relatively moisture absorbent and
has been found to stabilize the fabric structure and contribute to
the softness of the fabric. Because of its poor washability, the
inventors have found that these fire resistant fibers should not
comprise more than about forty percent of the intimate blend.
In general, the inventors have found that an intimate blend of
modacrylic and fire resistant viscose fibers may be used to form a
lighter weight fabric construction. The flame resistant yarns are
ring-spun from an intimate blend of at least about sixty percent
modacrylic fibers and up to about forty percent fire-resistant
viscose fibers. Preferably, the modacrylic fibers comprise between
about seventy-four percent and eighty percent of the intimate blend
and the fire resistant viscose fibers comprise between about twenty
percent and twenty-six percent of the intimate blend, even more
preferably a blend of 77/23 modacrylic/FR viscose. While a blend of
only modacrylic and FR viscose is preferred, minor amounts of other
fibers such as natural fibers like cotton or wool, or polymeric
fibers like polyester and the like could be added. In the
embodiment described herein, the inventors have learned that a yarn
size of between about 30/1 cc and 36/1 cc is quite suitable for
forming the fabric and apparel claimed herein, however other yarn
sizes are conceivable.
Turning now to the figures in general, the double-knit fabric for
the base layer apparel formed according to the present invention is
shown. While the embodiment described herein is a double-knit
construction, the fabric construction is not limited thereto. Those
skilled in the art will appreciate that a single, or multi-ply,
fabric satisfy the objectives of the inventors. For example, single
ply jersey knit is also within the scope envisioned. Other knits,
and even woven fabrics are contemplated.
As shown in FIGS. 1 and 2, a representative fabric 100 for the base
layer apparel comprises two surfaces or sides 110, 130. The machine
used to form the double-knit fabric is a Model 15 Mon 1680
NDL-84F-MEM circular knitting machine available from Monarch
Knitting of England. Circular knitting machines of this type
comprise a 30 inch knitting cylinder, with 80 feeds, and is
configured for 18-cut. Eighteen cut refers to the number (18) of
needles per inch and fabric so formed is known as 18-cut fabric.
The dial setting for this embodiment is "A-M-A-M-A-M-A-M," where A
represents a knit stitch and M represents a miss-stitch, also known
in the art as a float-stitch. The dial side setting forms the mesh
side of the double-knit fabric. The cylinder setup is best shown in
the diagram of FIG. 3, where each space represents a possible
needle position/action, or a miss, for the fabric pattern and the
two sides thereof. One exemplary machine setup comprises a 243 inch
revolution, set for 14.5 inches per one hundred needles, or 0.145
inches per needle.
Referring again to FIGS. 1 and 2, a representation of the two sides
of the double-knit fabric are shown. As shown in FIG. 1, the inner
side (preferably the side facing inwardly and against the skin of
the wearer of the apparel) has a tighter knit construction with the
courses and wales of the yarns 125 being more dense relative to the
outer open mesh side 130, shown in FIG. 2. In FIG. 1, the inner
side has openings between the yarns 125 that are barely visible to
the naked eye, whereas the openings 135 between the yarns 125 on
the open mesh side are substantially larger and more readily
visible.
As the inventors have found, when one side of the fabric is knitted
as an open mesh, having larger openings between yarns, and when the
yarns of the two sides of the fabric are in contact, wicking of
moisture is promoted. That is, having the two sides with different
yarns densities creates an affinity for moisture to move from a
wetted side to a dryer side. Thus, for example, when the side with
the greater stitch (course) density is worn against the skin,
moisture/perspiration will be drawn to the outer mesh side with the
more open structure. This open structure also provides for enhanced
air movement and ventilation, which serves to more easily evaporate
the moisture driven to the outer mesh surface. Alternatively, the
mesh side of the fabric may be worn as the inner layer against the
skin and the side with the greater stitch density may be worn as
the outer layer. One example of a type of base layer apparel
incorporating the double-knit fabric described herein is a T-shirt
400, shown generally in FIG. 4.
Exemplary fabrics formed as described herein were subjected to
numerous tests including: (1) Flame Resistance (Vertical Flame)
(ASTM D 6413); (2) Thermal Stability and Thermal Protective
Performance (NFPA 1971); (3) Pilling Resistance (Rando Tumble)
(ASTM D 3512); (4) Dimensional Change After Home Laundering (5
Cycles) (AATCC 135); (5) Water Vapor Transmission Rate (ASTM E 96);
(6) Antibacterial Finish Assessment (AATCC 100); and, (7) Static
Decay and Moisture Wicking (FTMS 191A, Method 4504).
To further promote wicking of moisture outwardly away from the
wearer of an article of apparel formed of the fabric described
herein, a wicking agent may be applied to the greige, or
unfinished, fabric during the dyeing process. While the particular
dyeing process is not important to the present invention, jet
dyeing is one suitable process for both dyeing and applying wet
chemicals to a fabric. More particularly, one wicking agent found
to be particularly effective at wicking moisture is ANWICK LW.TM.,
a proprietary product available from R.T. Anderson Enterprises of
Raleigh, N.C. When ANWICK LW.TM. is applied to a fabric, the
resulting fabric has a hydrophilic characteristic which allows for
moisture transport away from the body, permitting evaporation while
retaining the strength of the fibers comprising the fabric. Other
wicking agents compatible with the yarns and apparel uses are also
contemplated.
For base layer apparel that is worn under conditions likely to
promote microbial/bacterial growth, such as high humidity, an
anti-microbial treatment may be applied either during the dyeing
process or by subsequent padding of the wet dyed fabric. One
effective anti-microbial treatment is known as ATS ULTRA FRESH.TM.
MVN-2, a 2,4,4' tricholor-2' hydroxydiphenyl ether, available from
American Textile Specialties of Spartanburg, S.C. Other
anti-microbial agents may also be used that are compatible with the
fibers and safe to use in apparel worn next to the skin.
While the embodiment described herein above is described in detail,
it is apparent that other combinations of the modacrylic and flame
resistant viscose fibers could be used. For example, it is believed
any blend of at least about sixty percent modacrylic and up to
about forty percent flame resistant rayon will produce a
satisfactory fabric for use in the base layer apparel, regardless
of the knitting procedure. Also, as stated herein above, so long as
modacrylic and FR viscose are the primary constituents, smaller
amounts of other fibers may be added. In the same vein, other yarn
sizes, fiber denier, and knit or weave construction are
possible.
Certain other modifications and improvements may occur to those
skilled in the art upon a reading of the foregoing description. It
should be understood that all such modifications and improvements
have been deleted herein for the sake of conciseness and
readability but are properly within the scope of the following
claims.
* * * * *